1. Field of the Invention
The present invention generally relates to a cold weather hat for use during winter sporting activities. More particularly, the present invention relates to a thermally insulative hat, which may be selectively vented during winter sporting activities to more readily exhaust heat to the surrounding atmosphere via convective currents. The present invention thus provides users with a means to prevent bodily discomfort or overheating during rigorous winter sporting activities.
2. Description of the Prior Art
Key to success in any winter sporting activity is the requirement to dress warmly. It is noted that the human body ordinarily remains at a fairly constant temperature of 37° Celcius (98.6° Fahrenheit). It is very important that this body temperature be maintained and, since there is a continuous body heat gain from internal body processes, there must also be a continuous body heat loss to maintain body heat in balance. Excess heat must be absorbed by the surrounding air or lost by radiation. As the temperature and humidity of the environment in which a human body is active varies, the human body automatically regulates the amount of heat it gives off. However, the human body's ability to adjust to varying environmental conditions is limited. Furthermore, although the body may adjust to a certain (limited) range of atmospheric conditions, it does so with a distinct feeling of discomfort. The following is a brief discussion of how atmospheric conditions affect the body's ability to maintain a heat balance and the background information supporting the development of the present invention.
The human body gains and loses heat by radiation, convection, conduction, evaporation, and as a by-product of other physiological processes that take place within the body, namely the oxidation of food, other chemical processes, and by friction and tension within muscle tissues. Most body heat, however, is produced by the foods consumed by the individual, which body heat must be removed continuously or body temperature would steadily rise. The principal routes of body heat loss include radiation, conduction, convection, and evaporation. Radiation is the transfer of heat as infrared heat rays from a warmer object to a cooler object without physical contact. The human body loses heat by the radiation of heat waves to cooler objects nearby such as ceilings, floors and walls. If these objects are at a higher temperature, the human body absorbs heat by radiation. Incidentally, air temperature has no relationship to the radiation of heat to and from objects. Skiers, for example, are, on occasion, able to comfortably remove clothing in bright sunshine even though the air temperature is very low because the radiant heat from the sun is adequate to warm the skier. In a room at 21° C. (70° F.), about 60 percent of heat loss is by radiation in a resting person.
Conduction is the process by which body heat is transferred to a substance or object in contact with the body, such as chairs, clothing, jewelry, air or water. At rest, about 3 percent of body heat is lost via conduction to solid objects. The contact of air or water with the human body results in heat transfer by both conduction and convection. Convection is the transfer of heat by the movement of a liquid or gas between areas of different temperature. When cool air makes contact with the body, it becomes warmed and less dense. The less dense air then rises. Subsequently, cool air makes contact with the body and is carried away as it warms by conduction and becomes less dense. The faster the air moves, the faster the rate of convection. When at rest, about 15 percent of body heat is lost to the air by conduction and convention.
Evaporation is the conversion of a liquid to vapor. Water has a high heat of evaporation, and because of this characteristic, every gram of water (as found in perspiration) evaporating from the skin takes with it a relatively great deal of heat—on the order of about 0.58 kilocalories per gram of water. Under normal conditions, about 22 percent of heat loss occurs through evaporation. Under extreme conditions, about 4 liters of perspiration are produced each hour, and this volume can remove about 2,000 kilocalories of heat from the body. This is approximately 32 times the basal level of heat production.
Even though there are wide fluctuations in environmental temperature, the human body's homeostatic mechanisms can maintain a normal range for the internal body temperature. If the body heat production equals the body heat loss, the body maintains a constant core temperature near the earlier cited 37° C. Body heat losses may be classified in two general categories, namely, loss of sensible heat and loss of latent heat. Sensible heat is given off by radiation, convection and conduction. Latent heat is given off in the breath and by evaporation or perspiration. In perfectly still air, the layer of air around a body absorbs the sensible heat given off by the body and increases in temperature. The layer of air also absorbs some of the water vapor given off by the body, thus increasing the relative humidity. This means the body is surrounded by an envelope of moist air that is at a higher temperature and relative humidity than the ambient air. Therefore, the amount of heat the body can lose to this envelope is less than the amount it can lose to the ambient air. When the air is set in motion past the body, the envelope is continually being removed and replaced by the ambient air, thereby increasing the rate of heat loss from the body. When the increased heat loss improves the body heat balance, the sensation of a breeze is felt; when the increase is excessive, the rate of heat loss makes the body feel cool and the sensation of a draft is felt.
From the foregoing discussion, it is evident that the three factors, namely temperature, humidity, and air motion, are closely interrelated in their effects upon the comfort and health of winter sports enthusiasts. In fact, a given combination of temperature, humidity, and air motion will produce the same feeling of warmth of coolness as a higher or lower temperature in conjunction with a compensating humidity and air motion. The term given to the net effect of these three factors is known as the Effective Temperature. Effective Temperature cannot be measured by an instrument, but can be found on a special psychometric chart when the temperatures and air velocity are known. The combinations of temperature, relative humidity, and air motion of a particular Effective Temperature may produce the same feeling of warmth of coolness. However, they are not all equally comfortable. Relative humidity below about 15 percent produces a parched condition of the mucous membranes of the mouth, nose and lungs, and increases susceptibility to disease germs. Relative humidity above about 70 percent causes an accumulation of moisture in the clothing. For the best health conditions, relative humidity ranges from about 40 to 50 percent for cold weather and from 50 to 60 percent for warm weather.
As earlier stated, most of the body heat produced by the human body comes from oxidation of the food humans eat. The rate at which this heat is produced is referred to as the metabolic rate. Among the factors that affect the metabolic rate are the following: exercise, nervous system, hormones, body temperature, food ingestion, age and several other variables of lesser direct involvement, namely gender, climate, sleep, and malnutrition. During strenuous exercise activity, such as skiing or snowboarding, the metabolic rate may increase to as much as 15 times the normal rate; in well-trained athletes, the rate may increase to a rate 20 times the normal metabolic rate.
In this regard, adequate clothing protection for the winter sports enthusiast is essential. Adequate clothing protection should not only include means for retaining body heat in adjacency to the skin of the athlete, but also means for selectively releasing or venting body heat from areas in adjacency to the skin to help maintain a more agreeable body heat level. Without a means to release or vent body heat, it is noted that skiers often experience a great increase in body heat, which generally causes discomfort during those intervals between strenuous activities, which intervals are marked by relatively little bodily activity. Typically, the intervals of little bodily activity occur during ski lift or tow periods to the start of a ski run and the like. For example, after a strenuous downhill run, the body heat increases dramatically, but downhill motion causes air movement over the body, thus causing the removal of excess heat from the body. The period of strenuous exercise is countered with air motion and thus creates a sense of body heat balance. However, after the downhill run is complete and the skier becomes sedentary on a ski lift, the body heat is still at a high level, causing the body to perspire and overheat. During this period goggles may fog up as heat leaves the facial area exposed beneath an insulative hat and perspiration may build up on the superficial head surfaces, both of which events may cause bodily discomfort during the described period of inactivity.
It is estimated that as much as 50 to 80 percent of body heat is lost through the head of a strenuously exercising human body. In this regard, adequate head wear protection is essential for both retaining and venting body heat as may be required. It is noted that different types of head wear with vents have been developed in an attempt to aid users in the pursuit of maintaining a more leveled body heat balance. It is further noted that the prior art teaches a great variety of head wear or hats with air vents. Some of the more pertinent prior art relating to head wear incorporating venting systems and the like is described hereinafter.
U.S. Pat. No. 1,990,096 ('096 patent), which issued to Rothchild, discloses a Ventilated Hat. The '096 patent teaches a hat with ventilation means preferably enabled through the use of slide fastener or zipper means. Rothchild thus essentially claims a hat having a crown to cover the head of the wearer, which crown comprises at least one slit for communicating with the outer atmosphere. One end of the slit is disposed at a point adjacent the top of the crown and the other end of the slit terminates at a point adjacent the base of the crown. The slide fastener means are adapted to close the slit in selective degrees as desired by the user.
U.S. Pat. No. 2,051,084 ('084 patent), which issued to Patton, discloses an Adjustable Cap. The '084 patent teaches a cap comprising two similar substantially rectangular plies of fabric superimposed one on the other, which together constitute the crown and head band. The plies are joined together along one longitudinal edge and a short edge, thereby leaving the plies unjoined at the other longitudinal edge and at least partly along the last named short edge. An outward projection extends from each of the plies at the unjoined portion at the short edge thereof. The projections are adapted to overlap each other and form the cap to the head of the wearer. Further, adjustable fastening means are located along the unjoined longitudinal edges of the plies at the projections. A continuous cuff is secured to the unjoined longitudinal edges of the plies and is coextensive with the projections. The cuff comprises sufficient width so as to overlap the projections when turned upward.
U.S. Pat. No. 2,349,471 ('471 patent), which issued to Starbeck, discloses Headgear. The '471 patent teaches a ventilated head covering or headgear which comprises a plurality of similarly contoured pieces secured together. Certain of the similarly contoured pieces are selectively detached one from the other to provide flaps, which flaps are foldable back upon themselves to form openings in the crown. Mesh-like materials span the resultant openings and slide fasteners coact with the flaps and other pieces in the crown for fastening the flaps to the crown and close the openings.
U.S. Pat. No. 5,495,622 ('622 patent), which issued to Kaufman, discloses a Ventilated Hat. The '622 patent teaches an all weather runner's hat, the design of which promotes airflow around the head and hair of a person while, at the same time, deflecting rain. The Ventilated Hat comprises a generally hemispherical shell; a brim which is attached to the shell at an angle of about 15 degrees from horizontal and varies in width around the circumference; a number of vents positioned in the crown for ventilation; a headband; and a means of attaching the headband with spacers to create a novel air gap to allow air flow around the head and hair.
U.S. Pat. No. 5,642,526 ('526 patent), which issued to Thompson, discloses a Convertible Garment Having a Ventilation Opening and a Storage Pouch. The '526 patent teaches a garment wherein certain portions of the garment have ventilation openings incorporated into the design, which openings are preferably opened or closed via slidable fastening means or zipper means. A sublayer of fishnet-like mesh material is disposed at the opening for venting air from the garment to the outside atmosphere, which material may also be utilized to store the garment. In this regard, the garment may be condensed and stored in the mesh material which doubles as a storage pouch for the garment.
From a review of these patents and other prior art generally known in the relevant art, it will be seen that the prior art does not teach an insulative, ventable ski hat for enabling a skier to selectively vent body heat, which insulative ventable ski hat essentially comprises a superior vent portion and an inferior crown-receiving portion. It will be further seen that the prior art does not teach an insulative, ventable ski hat wherein the superior vent portion comprises an anterior-superior portion, a posterior-superior portion and a selectively-ventable vent aperture, the vent aperture being intermediate the anterior-superior portion and the posterior-superior portion. It will be further seen that the prior art does not teach an insulative, ventable ski hat wherein the vent aperture comprises open-closure means for selectively venting the vent aperture, the vent aperture being substantially elliptical in configuration. It will be further seen that the prior art does not teach an insulative, ventable ski hat comprising an elliptical vent aperture, which elliptical vent aperture necessarily comprises a major axis and a minor axis. The prior art does not teach an insulative, ventable ski hat wherein the major axis of the elliptically shaped vent aperture is medially aligned along a skier's head. Given the fact that a skier's head necessarily comprises a superior head surface, it will be seen that the prior art does not teach an insulative, ventable ski hat wherein the open-closure means is in spaced relation in superior adjacency to the superior head surface thus defining an insulative air layer, the open-closure means thus enabling a user to selectively vent body heat from the insulative air layer.
It will be further seen that the prior art does not teach an insulative, ventable ski hat wherein the vent aperture comprises a mesh fabric layer in inferior adjacency to the open-closure means, which mesh fabric layer and open-closure means together form a selectively-ventable, mesh-filtered vent. It will be further seen that the prior art does not teach an insulative, ventable ski hat wherein the open-closure means is defined by a zipper, which zipper comprises a main axis that coincides with the major axis of the substantially elliptical vent aperture. It will be further seen that the prior art does not teach a ventable ski hat wherein the ventable ski hat comprises a superficial fabric layer and a deep fabric layer, the superficial fabric layer comprising an insulative fabric material and the deep fabric layer comprising a moisture-wicking fabric material. Still further, it will be seen that the prior art does not teach an insulative, ventable ski hat wherein the major axis of the substantially elliptical vent aperture has a measured dimension ranging from about 5 inches to 6 inches and wherein the minor axis has a maximum measured dimension of about 1.5 inches.
The prior art thus perceives a need for an insulative, ventable ski hat for enabling a skier to selectively retain or vent body heat during strenuous winter sporting activities, as needed or desired by the skier, which insulative ventable ski hat essentially comprises a superior vent portion and an inferior crown-receiving portion. In this regard, the prior art perceives a need for an insulative, ventable ski hat wherein the superior vent portion comprises an anterior-superior portion, a posterior-superior portion and a selectively-ventable vent aperture intermediate the anterior-superior portion and the posterior-superior portion. Further, the prior perceives a need for an insulative, ventable ski hat wherein the vent aperture comprises open-closure means for selectively venting the vent aperture, the vent aperture being substantially elliptical in configuration when in a fully open state and substantially linear when in a fully closed state. Still further, the prior art perceives a need for an insulative, ventable ski hat comprising an elliptical vent aperture, which elliptical vent aperture necessarily comprises a major axis and a minor axis, the major axis of the elliptically shaped vent aperture being designed for medial alignment along a skier's head from the anterior-superior portion to the posterior-superior portion. The prior art thus perceives a need for an insulative, ventable ski hat wherein the open-closure means is designed to be in spaced relation in superior adjacency to the superior head surface of a skier, thereby defining an insulative air layer and the open-closure means thus enabling a user to selectively retain or vent body heat from the insulative air layer.
The prior art further perceives a need for insulative, ventable ski hat wherein the vent aperture comprises a mesh fabric layer in inferior adjacency to the open-closure means, which mesh fabric layer and open-closure means together form a selectively-ventable, mesh-filtered vent. Still further, the prior art perceives a need for an insulative, ventable ski hat wherein the open-closure means is defined by a zipper, the zipper comprising a main axis that coincides with the major axis of the substantially elliptical vent aperture. The prior art perceives an additional need for a ventable ski hat wherein the ventable ski hat comprises a superficial fabric layer and a deep fabric layer, the superficial fabric layer comprising an insulative fabric for retaining body heat in adjacency to the superior head surface and the deep fabric layer comprising a moisture-wicking material for conveying perspiration or liquid away from head surfaces. Still further, the prior art perceives a need for an insulative, ventable ski hat wherein the major axis of the substantially elliptical vent aperture has a measured dimension ranging from about 5 inches to 6 inches and wherein the minor axis has a maximum measured dimension of about 1.5 inches.